Heel holding device for safety ski bindings



Dec. 29, 1970 M K R ET AL 3,550,996

HEEL HOLDING DEVICE FOR SAFETY SKI BINDINGS Filed Sept. 6, 1968 7 Sheets-Sheet 1 \I I! 28 F} =1 11x11! v. 9 34 /5 7 325.9, 1012 33 30v 3 Fig.2

' I INVENTORS HANNES MARKER, ROLAND JUNGKIND ATTORNEYS 29, 1970 MARKER ETAL HEEL HOLDING DEVICE FOR SAFETY SKI BINDINGS 7 Sheets-Sheet 2 Filed Sept.

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m m K R A M 9 a 2 N v 4 N A 2 .A\3 0 U 3 I w [I III/ll I IA ROLAND JUNGKINDI ATTORNEYS Dec. 29, 1970 MARKER ETAL 3,550,996

HEEL HOLDING DEVICE FOR SAFETY SKI BINDINGS Filed Sept. 6, 1968 7 Sheets-Sheet 3 [14/ I I I //V A lll/ I;

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INVENTORS HANNES MARKER,

ROLAND JUNGKIND ATTORNEYS Dec. 29, 1970 MARKER ETAL 3,550,996

HEEL HOLDING DEVICE FOR SAFETY SKI B INDINGS v 7 Sheets-Sheet 4.

Filed Sept. 6, 1968 f I! I I 42 INVENTORS HANNES MARKER,

BY ROLAND JUNGKIND mfi %%M%,g

ATTORNEYS Dec. 29, 1970 MARKER ET AL 3,550,996

HEEL HOLDING DEVICE FOR SAFETY SKI BINDINGS Filed Sept. 6, 1968 7 Sheets-Sheet 5 Fig.9

INVENTORS 43 41 47 l 42 HANNES MARKER,

BY ROLAND JUNGKIND JWQW,%&%&

ATTORN EYS Dec. 29, 1970 MARKER ETAL HEEL HOLDING DEVICE FOR SAFETY SKI BINDINGS 7 Sheets-Sheet 6 Filed Sept. 6, 1968 H O 6/? 2 6 2 9 8 8 u F 6 6 2 5 3 v 2 3 3 3 8 H w 8 5 8 6 7 4 5 7 xl\ IM 6 3 7 5 v?|\ fi/ DW 3 2 7 s E E m /Y( w RAIJ 4 7 \m 8 4 L v I 5 )5 5 R mm M V M N U W M J SD EN N A NL A0 HR ATTORNEYS Dec. 29, 1970 MARKER ETAL HEEL HOLDING DEVICE FOR SAFETY SKI BINDINGS 7 Sheets-Sheet 7 Filed Sept. 6, 1968 Fig .14

s m D NMW K &m G T N A Um J D 7 N A m R Ym Bi United States atent O 3,550,996 HEEL HOLDING DEVICE FOR SAFETY SKI BINDINGS Hannes Marker, Garmisch-Partenkirchen, and Roland Jungkind, Farchant, Germany, assignors to Hannes Marker, Garmisch-Partenkirchen, Germany Filed Sept. 6, 1968, Ser. No. 758,034

Claims priority, application Germany, Sept. 8, 1967, 1,578,855; July 29, 1968, 1,703,915 Int. Cl. A63c 9/084 U.S. Cl. 280-1135 16 Claims ABSTRACT OF THE DISCLOSURE A heel holding device for safety ski bindings for a swingable supporting piece for a sole holder and a closure pedal which forms the coupler of a four-joint mechanism which functions under the influence of a spring and which upon the introduction of a ski boot into the binding automatically assumes its locked position with the spring acting upon the supporting piece with the interposition of a tip lever.

The present invention relates to a heel holding device for safety ski bindings which has a swingable supporting piece for a sole holder and a closure pedal which forms the coupler of a four-joint mechanism; which is under the action of a spring; and which upon the introduction of a ski boot into the binding automatically assumes its locked position and can be opened whenever desired by, for instance, a slight pressure of the ski pole on a release or which opens automatically upon the occurrence of an excessive tensile force directed approximately vertically upward.

Known heel holding devices of this type have an essential drawback which resides in the fact that in the locked position of the heel holding device the spring, with the release pressure adjusted to a preselected value, constantly acts on the supporting piece for the sole holder. This means that any forces acting on the sole holder which are directed approximately vertically upward and which do not endanger the leg of the skier and therefore do not lead to release, such as might occur, for instance, as a result of bumps upon skiing, must be taken up fully and completely by the leg of the skier, which leads to disagreeable strains and premature fatigue.

The main object of the present invention is to remedy this situation by providing a heel holding device of the aforementioned type so arranged that a force acts on the sole holder in the direction of release up to a given adjustable release point against an elastic progressively increasing resistance which dampens the force, this resistance, however, collapsing at the release point.

.Starting from a heel holding device for safety ski bindings which has a swingable supporting piece for a sole holder and a closure pedal which forms the coupler of a four-joint mechanism and is under the influence of a spring and which upon the introduction of a ski boot into the binding automatically assumes its locked position and can be opened when desired, for instance, by exerting a slight pressure with the ski pole on a release or which opens automatically upon the occurrence of an excessive tensile force directed approximately vertically upward, the aforementioned object is achieved in accordance with the present invention in the manner that the spring acts on the supporting piece with the interposition of a tip lever, the free end of the one arm of which is connected with the supporting piece, while the other end thereof, which is acted upon by the spring, is positively guided by a lever held swingably in a housing and is extended beyond the point of attack of the spring force; that there is provided a part fastened to the housing and against which the free 3,550,996 Patented Dec. 29, 1970 end of the spring-loaded arm of the tip lever rests in the locked position; and that there is present a least one stop fixed to the housing which is intended to cooperate with the tip lever and, after a certain movement of the sole holder in the direction of unlocking, effects a movement of the tip lever beyond the tip point.

By this development the result is obtained that the tip lever, before the release point of the supporting piece is reached, moves as a rigid unit against the spring force and is moved back by the latter again upon the reduction of the force.

On the other hand, if the movement takes place with correspondingly strong force up to the release point, the tip lever collapses and no longer opposes movement of the sole holder into the release position. The swinging of the supporting piece for the sole holder and the closure pedal out of the release position into the locking position takes place with practically no force with respect to the spring which applies the resistance to release.

For the adjustment of the heel holding device to different boot lengths and in order to vary the pressure of the ski boot against a toe holding device, the housing is advisedly made displaceable in the longitudinal direction of the ski by the interposition of a second spring on a base plate which is fastened to the ski.

As a special development of the subject matter of the invention, there can be used as a spring a coil compression spring which acts via a forked spring washer against the pivot point of the tip lever, said spring in its turn resting against the housing.

The coil compression spring preferably rests against the housing with the interposition of a spring washer a convex part of which engages in a cup-shaped indentation in the housing and forms one arm of a bellcrank lever, the free end of the other arm of which serves as stop for the tip lever. In this connection, the lever arm which forms the stop can bear a pushbutton which extends upward through the housing and by the actuation of which it can be brought, in opposition to a restoring force, into the sphere of action of the tip lever. In this way there is created a simple possibility for opening the heel holding device whenever desired, since upon actuation of the pushbutton with simultaneous slight pulling on the sole holder its supporting piece immediately swings into the unlocked position.

As a further development of this inventive concept, the pushbutton can be supported rotatably and have in axial direction an extension which extends up into the sphere of action of the tip lever, which extension is provided with steps or is of spiral shape, so that an adjustment of the release hardness which is dependent upon the distance is possible by turning the pushbutton.

In general, it is the heel holding device which presses the ski boot resiliently against the toe holding device to produce a firm union with the ski. There are now on the market, inter alia, toe binding the release force of which is variable for safety opening upon turning falls as a function of the pressure. Since in general the release force of the toe binding is in a given relationship to the release force of the heel binding, another object of the present invention is to provide a possibility in connection with the new heel holding device with which the release force, as a function of the pressure selected, automaticallv adjusts itself properly to the release force of the toe binding.

For this purpose, as a special embodiment of the invention, if the housing of the toe holding device is held displaceable in the longitudinal direction of the ski on a base plate which is fastened to the ski with the interposition of a second spring which effects the pressing of the ski boot against a toe binding, the first spring can act via the swing lever which effects the positive guidance of 3 the arm of the tip lever against said arm and can be supported in a swingable cage and the spring cage can be positively guided as a function of the initial tension of the second spring.

The heel holdin device developed in this manner therefore requires only an indicating device for the pressure, while no special indicating device for the automatically self-adjusting release force is required.

The spring cage is advisedly held on the housing by two coaxial journal pins and has at least one guide slot into which there engages .a guide pin which is fastened to the ski parallel to the journal pins.

As a stop which controls the tipping of the tip lever for the safety opening of the device there is preferably used a slotted lever which at its free end has a recess which receives the pin forming the toggle joint and is supported on a shaft which simultaneously forms a pivot point of the four-joint mechanism on the housing. In this Way, the size of the heel holding device can be kept small and its weight thus kept low, which is also essential for the use and thus for the sale of the device.

As a particular development of this heel holding device, it has proven advantageous that a stop piece which for the intentional opening of the device effects the tipping f the tip lever is swingably supported on the housing and is movable against the force of a return spring via its free end to a position in front of the extension of the arm of the tip lever which is acted on by the spring. In this connection, there can be provided for the swinging of the stop piece a swing lever which can be actuated against the force of a return spring, which swing lever can be supported on a pin which at the same time forms a pivot point of the four-joint mechanism on the housing. Furthermore, a common return spring can be provided for the stop piece and the swing lever.

The movement of the toggle joint away from the sole holder is advisedly limited by the slotted lever and the movement towards the sole holder is advisedly limited by extending the tip-lever arm acted on by the spring beyond the toggle joint.

Two preferred embodiments of the subject matter of the invention are described in detail below with reference to the accompanying drawings, in which:

FIG. 1 shows the heel holding device of the invention in accordance with a first embodiment, seen in a central longitudinal section;

FIG. 2. is a top view of FIG. 1;

FIG. 3 is a showing corresponding to FIG. 1 but in position directly before the automatic unlocking;

FIG. 4 is a showing corresponding to FIG. 1 but in unlocked condition;

FIG. 5 is a showing corresponding to FIG. 1 but in position directly before the manual unlocking;

FIG. 6 shows the heel holding device in accordance with the invention in accordance with a second embodiment, seen in central longitudinal section;

FIGS. 7-9 are each a cross-section along the lines VIIVII, VIIIVIII and IXIX of FIG. 6;

FIGS. 10-12 are each a longitudinal section through the heel holding device along the lines X-X, XIXI and XIIXII of FIG. 7;

FIG. 13 is a showing corresponding to FIG. 6 of the heel holding device, but in condition directly before the automatic unlocking;

FIG. 14 is a showing corresponding to FIG. 6 but in unlocked condition; and

FIG. is a showing corresponding to FIG. 6 of the heel holding device in the condition directly before the manual unlocking.

In the case of the first preferred embodiment of the heel holding device of the invention which is shown in FIGS. 1 to 5, there is provided a base plate 1 which serves for fastening the device to a ski. For this purpose, screw holes (not shown) are provided in the base plate. The longitudinal sides of the base plate are bent upward and inward and form guideways 2, 3 (see FIG. 2) for a housing 4 which is held for displacement in longitudinal direction on the base plate. In the side walls of the housing there are supported two horizontal shafts 5, 6. These two shafts form the stationary joints of a four-joint mechanism Whose coupler 7 forms a supporting piece for a sole holder 8. One free end of the coupler 7 which is bent at an angle forward serves as closure pedal 9. To permit adaptation to different ski boot soles, the sole holder is held on the supporting piece in adjustable height and detachable in known manner. This supporting piece which forms the coupler of the four-joint mechanism is articullated by means of the shafts 10, 11 to the swing members 12, 13, the swing member 12 being supported on the shaft 5 and the swing member 13 on the shaft 6 in the housing 4. In order to cover the top of the intermediate space which is necessary for functional reasons between the housing 4 and the supporting piece 7, there is used an elastic packing 14, consisting, for instance, of rubber or soft plastic. On the upper end of the supporting piece there is furthermore provided a lug 15 to which a so-called safety strap can be fastened.

In accordance with the main feautre of the present invention, a coil compression spring 16 provided to produce the release hardness acts via a tip lever on the supporting piece 7. The tip lever consists of the two lever arms 17, 18, and the toggle joint 19. The free end of the lever arm 17 is supported on the shaft 10 of the supporting piece. The free end of the lever arm 18 is pivotally connected via a shaft 20 with another lever 21 which in its turn is held to the housing 4 swingable on the shaft 5. The spring 16 acts via a spring washer 22, swingably held on the shaft 20, against the lever arm 18. Said lever arm is extended beyond the shaft 20. The extension is designated 23 and forms a double actin supporting nose which in the locked position of the device comes against the end of the swing member 13 and thus rests via the shaft 6 against the housing 4.

The spring 16 rests, with the interposition of a spring washer 24, against the housing 4. This spring washer has a convex portion by means of which it engages in a cup-shaped indentation in the housing. The spring washer 24 has an extension 25 bent off at an angle, the free end of which serves as stop for the supporting nose 23 of the lever arm 18. The extension bears a pushbutton 26 which extends outward through a hole in the upper wall of the housing and by the actuating of which the free end of the extension can be brought into the sphere of action of the supporting nose 23. Upon the actuation of the pushbutton, the spring 16 is loaded somewhat unilaterally by the swinging of the spring washer 24, so that a return moment is produced which, upon release of the pushbutton, brings the latter back into its initial position again. The pushbutton 26 is rotatably held on the extension 25 and has an extension 27 which extends into the sphere of action of the supporting nose 23 on the lever arm 18. This extension is stepped down in size, so that, depending on the angular position of the pushbutton, a greater or smaller distance is present between the supporting nose 23 and the extension 27. In this way, by turning the pushbutton, it is possible to effect an adjustment of the hardness of release which is dependent on the path.

On its righthand end, as seen in FIGS. 1 to 5, the base plate 1 has a bearing pedestal 28 for an adjustment pin 29. This pin has a threaded hole into which a screw bolt is screwed. This bolt is held in nonrotatable manner on the crossmember of a U-shaped strap 31, the legs of which are swingably supported on the shaft 5 in the housing 4. The adjustment pin 29 is milled for better manipulation on the free end thereof extending out of the bearing pedestal 28 and is furthermore provided with a slot for the insertion of a coin, for instance. Over the part of the adjustment pin which extends into the housing there is placed a coil compression spring 32,

the one end of which rests against the bearing pedestal 28, while its other end acts on a flange 33 on the inner end of the adjustment pin. This spring serves to press a ski boot against a toe binding. If no ski boot is in the binding, then this spring is completely relaxed. By turning the adjustment pin 29, the distance of the shaft from the bearing pedestal 28 can be changed. In this way it is possible on the one hand to adjust the device to a different length of ski boot and on the other hand also to vary the application pressure.

The swing member 12 of the four-joint mechanism and the lever arm 18 of the tip lever for structural rea sons do not lie in the central vertical longitudinal plane of the device. They are each present once on both sides of this plane and rigidly connected by crossmembers. The crossmember for the two parts of the lever arm 18 forms the supporting nose 23. The two parts of the swing member 12 are connected with each other by a crossmember 34 which at the same time serves as stop for the lever arm 17 of the tip lever and thus limits the pushing through thereof towards the supporting piece 7.

FIG. 4 shows the heel holding device in unlocked condition. Upon the introduction of a ski boot into the binding, the heel comes into contact with the closure pedal 9 and swings the latter, together with the sole holder 8 and the swingv members 12, 13, into the locking position shown in FIG. 1. In this connection, the tip lever 17, 18, 19 is stretched and brought into its other position under the influence of the coil compression spring 16. FIGS. 1, 3 and 5 show the heel holding device in locked condition but without pressing action towards the toe binding. This application pressure is effected upon the introduction of a ski boot into the binding in the manner that the boot, via the four-joint mechanism, pushes the entire housing 4 to a greater or lesser extent towards the right, as seen in the drawings, against the force of the coil compression spring 32. Introduction into the binding takes place without the exertion of practically any force in view of the low initial stress of the spring 16 to be taken into consideration for the safety release.

-A manual opening of the heel holding device is effected for instance, by pressing with a ski pole against the pushbutton 26 so that the free end of the extension 25 bearing said pushbutton comes in front of the supporting nose 23 of the tip-lever arm 18, as shown in FIG. 5. Upon the lifting of the heel, the tip lever is now immediately pressed beyond the tip point under influence of the crossmember 34 so that the spring no longer acts on the supporting piece 7, whereby the latter can be swung practically without force further upward into the unlocked position shownin FIG. 4.

If during skiing a tensile force directed approximately vertically upward should now act on the sole holder 8, the sole holder can move upward against the force of the coil compression spring .16, since before reaching the release point, the tip lever acts in this connection as. a rigid unit. By corresponding design of the four-joint mechanism, there is assured a movement of the sole holder which adapted to the movement of the rear end of the sole of the ski boot. Upon reduction of the force acting on the sole holder, the spring 16 via the tip lever presses the supporting piece together with the sole holder back into the initial position. If now, however, a higher force acts on the sole holder 8, the spring is compressed to such an extent that the supporting nose 23 of the tip-lever arm 18 comes to rest against the extension 27 of the pushbutton 26, as shown in FIG. 3. In this way, further swinging of the tip lever as rigid unit is prevented and the tip lever, under the influence of the crossrnernber 34, is forced through up to the tip point, whereupon the resistance opposing the movement of the sole holder collapses, so that the sole holder can swing suddenly and practically without force into the unlocked position.

FIGS. 6-15 show a second preferred embodiment of the heel holding device of the invention which has a base plate 41 which can be screwed onto a ski. As in the embodiment described previously, the longitudinal sides of the base plate are bent upward and inward and form guideways 42, 43 (see in particular FIGS. 7 to 9') for a housing 44 which is held displaceably in longitudinal direction on the base plate. In the side walls of the housing there are supported two horizontal shafts 45, 46 which form the fixed joints of the four-joint mechanism, a supporting piece for a sole holder 48 serving as coupler 47, for same. One free end of the coupler which is bent at an angle forward again forms a closure pedal 49. For adaptation to ski boot soles of different thickness, the sole holder is held in adjustable height and detachably on the supporting piece 47. This supporting piece is articulated by means of the shafts 50, 51 to swing members 52, 53, the swing member 52 being supported on the shaft 45 and the swing member 53 being supported on the shaft 46 in the housing 44. The supporting piece 47 is provided at its upper end with an approximately horizontal wall 54 which extends away from the sole holder and which in the closed condition of the device adjoins the upper wall of the housing 44.

The base plate 41 has two ribs 55 which extend as an extension of the longitudinal sides of the base plate past the closure pedal 49 in the direction towards the toe'ibinding. In normal skiing position, the heel part of the sole, indicated in dashed line and designated 56, rests on the ribs 55, while the sole holder 48 grasps above the upper edge of the sole. A strap 57 is formed from the base plate and extends vertically upward. A threaded pin 58 is held in non-rotatable and axially non-displaceable manner in a slot open at the top provided in said strap. On this pin there is screwed a threaded bushing 59 which at its inner end has a flange 60, while in its outer end there is screwed and pinned a screw 61. A coil compression spring 62, the outer end of which rests against a spring Washer 63 formed by a part of the holder body 64, is supported on the said threaded bushing.

The said holder body extends from the rear into the housing 44. Its two side walls 65 are each provided at their free end with a horizontal swing pin 66 which is transverse to the longitudinal direction of the ski (see FIGS. 10 and 11). These swing pins are coaxial to each other. The upper wall of the holder body 64-which wall is not as long as the side walls-bears ascale (not shown) to indicate the pressure against the toe binding and thus at the same time the hardness of release of the heel holding device. Within the housing 44 directly alongside the side walls of the housing there are two stiffening plates 67, 78 of mirror symmetry the exact shape of which can be noted from FIG. 10. At their lower end they each have an inward bent lug 69 which half engages in fork-like manner over the threaded bushing 59. The two lugs 69 together form a spring washer against which the inner end of the pre-stressed coil compression spring 62 acts, and presses it in unloaded condition of the heel holding device against the flange 60 of the threaded bushing 59 (see FIG. 14). The stiffening plates 67, 68 are firmly connected via the shafts 45, 46 with the housing 44 (see FIGS. 7, 8 and 10).

The heel holding device is symmetrical with respect to its vertical longitudinal central plane. For this reason, all levers, insofar as they do not lie in this plane, are present twice. Since they are, however, congruent and lie coaxially with respect to each other, reference will be had, for simplicity in description and better understanding, in all cases only to one lever. However, the fact that two of them are present can be noted from FIGS. 7 to 9.

A tip lever consisting of the two arms 71 and 72 and the toggle joint 73 is articulated at the one side by means of a shaft 74 to the swing member 52 and on the other side by means of a shaft 75 to a lever 76. The lever 76 is swingably supported on the shaft 45 in the housing 44. The two parts-present for the reason just explainedwhich together form the lever 76 are connected with each other by a crossarm 77 of concave curvature. Against this arm there rests a roller 78 which, with the interposition of a spring washer 79, is under the influence of a coil compression spring 80. This coil compression spring rests against a spring washer 81 which forms part of a spring cage 82. The spring cage 82 is swingably supported in bore holes of the stiffening lates 67, 68 by two coaxial journal pins 83. The two side walls of the spring cage each have an elongated hole 84 in which the roller 78 is guided (see in particular FIG. 11). Furthermore, each side wall ofthe spring cage also has a guide slot 85 into each of which slots a separate swing pin 66 of the holder body 64 engages.

On the shaft 46 there is furthermore supported a slotted lever 86 which at its free end has a recess (slot) traversed by the pin which forms the toggle joint 73. On both sides of the slotted lever 86 there is provided on the shaft 46 a plastic sleeve 87 against which there is provided on the shaft 46 a plastic sleeve 87 against which the tip-lever arm 72 rests via an extension 88 which extends beyond the shaft 75. At its other end, the tip-lever arm 72 has an extension 89 which extends beyond the toggle joint 73 and by coming against the shaft 74 limits the movement of the toggle joint towards the sole holder. The movement of the toggle joint away from the sole holder is limited by the slotted lever 86.

On the shaft 46 there is furthermore supported a release lever 92 which is swingable against the force of a return spring 91 and serves to actuate a stop piece 93. This stop piece is swingably held on the stiffening plates 67, 68 and is also under the influence of the return spring 91. The spring holds the release lever and the stop piece in their normal positions shown in FIGS. 6 and 10 to 14. The release lever 92 also consists of two congruent coaxial parts which are connected to each other by an arm which serves as actuating lever and has an indentation 94 for the insertion, for instance, of the tip of a ski pole.

FIG. 14 shows the heel holding device in unlocked condition. Upon the introduction of a ski boot into the binding, the heel comes into contact with the closure pedal 49 and swings the latter, together with the sole holder 48 and the swing members 52, 53 into the locked position shown in FIG. 6. In this connection, the tip lever is brought out of the one limit position into the other, it being at all times under the influence of the coil compression spring 80 via the lever 76. At the same time, furthermore, upon the introduction of the ski boot into the binder, the housing 44 with all parts connected thereto is moved rearward against the force of the coil compression spring 62, i.e., to the right in the drawings. The tensioning of the compression spring 62 results in the pressing of the ski boot against the toe holding device. This pressure can be varied by actuating the screw 61. If the threaded bushing 59 is screwed further onto the threaded pin 58, the pressure is increased. On the other hand, if it is unscrewed from the threaded pin, the pressure is reduced. In unlocked condition, as shown in FIG. 14, however, the coil compression spring 62 is still under the established initial tension. It is clear that it is also possible to a limited extent by actuating the screw 61 to adapt the device to different sizes of ski boot without for this purpose having to shift the base plate on the ski.

However, the spring cage 82 cannot participate in the movement of the housing 44 towards the rear upon the introduction of the ski boot, since the swing pins 66 of the holder body 64 engage into the guide slot 85 of the spring cage. In this way, upon a movement of the housing 44, with respect to the base plate 41, the spring cage 82 is positively imparted a swinging movement around the journal pins 83. This swinging movement is positively transferred to the roller 78 which is supported in the elongated holes 84 of the spring cage. There thus results for this roller, depending on the size of the pressure selected, a different point of rest on the curved arm 77 of the lever 76. This has the result that the moment produced by the compression spring 80 referred to the shaft 45 changes as a function of the pressure, as a result of which in each case a different amount of resistance opposes the action of the force on the sole holder up to release after a like path which always remains the same. As pointer to indicate the pressure adjusted and thus also the release force on the scale on the top of the holder body 64, there serves the edge, sliding thereover, of the downward extended wall of the housing 44.

A .manual opening of this heel holding device is effected by pressure on the release lever 92. As can be noted from FIG. 15, by the swinging of the release lever, the stop piece 93 is also swung, so that its free end comes to rest in front of the extension 88 of the tip-lever arm 72. If the heel of the ski boot is now lifted, then there instantaneously takes place a movement of the toggle joint 73 beyond the tip point into the other limit position. At first there results in this connection only an insignificant swinging of the lever 76 and thus a practically unnoticeable increase in the spring force of the coil compression spring 80 which then acts to unlock when the toggle joint has reached the tip point. Upon abatement of the pressure on the release lever 92, the latter and the stop piece 93 come back into their initial position under the influence of the return spring 91.

If during skiing a pulley force directed approximately perpendicularly upward acts on the sole holder 48, then the sole holder can move upward in opposition to the force of the coil compression spring 80, since before the release point is reached, the tip lever acts in. this connection as a rigid unit. Upon the abatement of the force acting on the sole holder, the coil compression spring 80 presses the supporting piece with the sole holder back again via the tip lever into its starting position. If, however, a larger force acts continuously on the sole holder 48, then the four-joint mechanism and thus also the tip lever are swung to such an extent that the bolt forming the toggle joint 73 comes against the end of the recess (slot) of the slotted lever 86 and is forced through by the latter. In this way, the resistance opposing the movetment of the sole holder collapses, so that the sole holder can swing practically without force and suddenly into the unlocked position.

As a modification of the embodiment of the heel holding device of the invention which has just been described, it is also possible to swing the spring case independently of the pressing pressure in order thereby to obtain an adjustment to different release forces with constant damping path. Such an embodiment may be advantageousin the same way as the one first describedin cases in which the heel holding device can be used to cooperate with a toe holding device which does not require a very specific pressure for its safety release.

What is claimed is:

1. In a heel holding device for safety ski bindings which has a swingable supporting piece for a sole holder and a closure pedal which forms the coupler of a fourjoint mechanism and is under the influence of a spring, and which, upon the introduction of a ski boot into the binding, automatically assumes its locked position and can be opened at will, for instance by slight pressure applied by the ski pole on a release, or automatically upon the occurrence of an excessive pulling force directly approximately vertically upward, the improvement comprising a tip lever (17, 18, 19; 71, 72, 73) interposed between the spring (16; 80) and the supporting piece (7; 47), one end of said tip lever (17; 71) being connected with the supporting piece and the other end (18; 72) being acted on by the spring, a housing, a lever (21; 76) swingably supported in said housing (4; 44), and extending beyond the point of attack of the spring force positively guiding the other end of said tip lever, a part (6; 46) fastened to the housing and against which the other end (23; 88) of the tip lever rests in the locked position, and at least one stop (27. 25'. 86, 93) which is fastened to the housing and intended to cooperate with the tip lever, which stop, after a certain movement of the sole holder (8; 48) in the direction of unlocking, effects a movement of the tip lever beyond the tip point.

2. In a heel holding device according to claim 1, the further improvement of the housing (4; 44) being held displacea'bly in the longitudinal direction of the ski on a base plate (1, 41) fastened to the ski, with the interposition of a second spring (32, 62) which effects the pressing of the ski boot against a toe binder.

3. In a heel holding device according to claim 2, the further improvement of the first spring (80) acting via the swing lever (76) which effects the positive guidance of the tip lever and is supported in a swingable cage (82) and that the spring cage is positively guided as a function of the initial tension of the second spring (62).

4-. In a heel holding device according to claim .3, the further improvement of the spring cage (82) being held on the housing (44) by two coaxial journal pins (83) and having at least one guide slot (85) into which there engages a guide pin (66) which is fastened on lel to the journal pins.

5. In a heel holding device according to claim 3, the further improvement of a slotted lever (86) being provided which at its free end has a recess (slot) which receives the pin (73) forming the toggle joint, said lever being. supported on a shaft (46) which simultaneously forms an articulation point of the four-joint mechanism on the housing.

6,; In a heel holding device according to claim 3, the further improvement of a stop piece (93) being provided which effects the tipping of the tip lever for the manual opening of the device 'which is swingably supported on the housing (44) and the free end of which is movable, against the force of a return spring (91), in front of the extension (88) of the arm (72) of the tip lever which is acted on by the spring (80).

7. In a heel holding device according to claim 6, the further improvement of a swing lever (92) being provided for the swinging of the stop piece (93) which can be actuated in opposition to the force of a return spring (91), said lever being supported on a shaft (46) which simultaneously forms an articulation point of the four-joint mechanismon the housing.

81 In a heel holding device according to claim 7, the further improvement of a colmmon return spring (9 1) being provided for the stop piece (93) and the swing lever (92).

'9. In a heel holding device according to claim 3, the further improvement of the movement of the toggle joint (73) away from the sole holder (48) being limited by the slotted lever (86) and the movement towards the sole holder being limited by an extension (89) of the tip-lever the ski paralarm (72) acted on by the spring beyond the toggle joint.

10. In a heel holding device according to claim 3, the further improvement of the free end of the tip-lever arm (71) not acted on by the spring ('80) being connected via a swing member (52) of the four-joint mechanism with the supporting piece (47).

11. In a heel holding device according to claim 1, the further improvement of said spring being a coil compression spring (16) which acts via a forked spring washer (22) on the articulation point (20)) of the top lever (17, 18, 19) and in its turn rests against the housing (4).

12. In a heel holding device according to claim 11, the further improvement of the coil compression spring (16) resting against the housing (4) with the interposition of a spring washer (24), a convex part of which engages in a spherically shaped indentation of the housing and forms an arm of a bellcrank lever, the other arm (25) of which serves at its free end as stop for the tip lever.

13. In a heel holding device according to claim 12, the further improvement of the lever arm (25 which forms the stop bearing a pushbutton (26) wihch extends upward through the housing and by the actuation of which it can be brought, in opposition to a returning force, into the sphere of action of the tip lever (17, 18, 19).

14. In a heel holding device according to claim 13, the further improvement of the pushbutton (26) being rotata'bly supported and being provided in axial direction with an extension (27) which extends up into the sphere of action of the tip lever and is spiral or stepped-down.

15. In a heel holding device according to claim .1, the further improvement of the point of articulation of the tip lever (17, 18, 19) on the supporting piece (7) coinciding with one (10) of the coupler joints thereof.

16. In a heel holding device according to claim 1, the further improvement of the point of swing of the swing lever (21) which holds the one arm (18) of the tip lever coinciding with an articulation point (5) of the four-joint mechanism on the housing (4).

References Cited UNITED STATES PATENTS 3,125,349 3/1964 Schweizer 28011.35(HA) 3,199,885 8/1965 Smolka et a1. 28011.35(HA) 3,366,394 1/1968 Shimizu 280-1l.35(HA) 3,391,944 7/1968 Shimizu 28011.35(HA) 3,445,124 5/1969 Heckl 280--ll.35(HA) BENJAMIN HERSH, Primary Examiner M. L. SMITH, Assistant Examiner 

